The term “abutment pump” is used herein to refer to a device comprising a movable partition separating the inlet and outlet streams within a stator chamber or housing and a rotor that rotates within the chamber to cause sequential intake, compression, and the exhaust of a fluid medium such as a gas, a liquid, or combination thereof. The term, therefore, comprehends not only devices that cause fluid movement but also devices that compress or pressurize fluids with or without ignition or combustion. Further, the term “abutment pump” embraces a reverse operation in which fluid drives a rotor rather than the rotor driving the fluid, i.e., in reverse operation every pump is effectively a motor.
One example of an abutment configuration is shown in U.S. Pat. No. 2,238,395 to Nittka. The pump in the Nittka patent comprises a rotor working in unison with a flapper requiring numerous components. The device is characterized by the complexity of the many parts required to manipulate the flapper.
Another example of an abutment configuration is shown in U.S. Pat. No. 715,933 to Allen. The engine and pump in the Allen patent comprises dual abutments working in unison with rotary valves with exhaust stream traveling through a port in the rotor expelled through the driveshaft. The device is complicated and requires several parts working in combination with the abutments.